140
Fault
Cause
Action
Steering torque is
insufficient
Loss flow of steering pump is inadequate. Inspect or replace the steering pump
Pressure change of the safety pressure
valve
Adjust its pressure (pressure)
Steering pump leaks seriously inside.
Repair or replace
Lift arm raising
force or bucket
tilting force is
inadequate
Oil seal of the cylinder is worn or
damaged
Change oil seal
Distribution valve is excessively worn,
the fitting gap between valve rod and
valve body exceeds the specified value.
Dismount and repair, to make the
clearance reach to the required value
or replace the distribution valve
Pipeline system leaks oil.
Find out the leaking point and remove
it.
The working pump/steering pump
seriously leaks inside.
Replace working pump//steering pump
Safety valve is adjusted improperly; the
system pressure is too low.
Adjust the system pressure to the
specified value
Oil tube and oil filter is blocked
Clean oil filter and change oil
After parking, the
pressure of air
reservoir drops
quickly
The inlet valve of pneumatic brake is
stuck by dirt or damaged
Brake continuously several times to
blow off dirt. Replace the valve.
Pipe connector is loose or pipe is
broken
Tighten the connector or replace the
brake tube.
One way valve of air inlet of air
reservoir is not sealed or pressure
controller is not sealed
Check the reason for no sealing. If
necessary, replace.
Air
leakage
of
brake system
Pollution sources: oil, water, dust and
impurity
Clean pipe line
With irregular brake oil
With regular brake oil
Air leakage resulting from worn washer
Clean the cylinder body, replace piston
washer
Brake slack
Not exhausting air in the hydraulic pipe
line completely
Release air in the hydraulic pipe line
Wearing parts wear
Replace consumable parts
Pressure of the
brake barometer
growing slowly
Pipe connector is loose
Tighten the connector
Air compressor working abnormally
Inspect the condition of air compressor
Oil outlet plug screw of separator of oil and
water not being closed tightly
Close it tightly again
Air inlet of brake valve or eardrum
without seal
Inspect and clean the internal brake
valve and find out the causes
Air outlet orifice of pressure controller
plug or check valve and eardrum
leakage
Clean air outlet orifice, inspect check
valve and the causes resulting eardrum
not sealing not except
Replace the drier of the whole machine
Brake fails
No or few liquid in booster pump oil cup Fill oil cup of booster pump with oil
Oil inlet valve and hydraulic washer
wear
Replace oil inlet valve, hydraulic
washer
Piston blocked
Replace the whole components
Oil
leakage
of
brake system
Oil leakage at the connector between
end cover and hydraulic cylinder body
Replace consumable parts
Oil leakage of center seal ring
Leakage at the connector between oil
cup and end cover
Inspect whether the oil cup assembly
tightened or not or replace consumable
parts
When brake acts,
pedal rebounds
Air exists in the braking line
Air is discharged from the braking line
